Sound muffler



S. M. CURIONI July 1, 1958 SOUND MUFFLER Filed April 4, 1955 VINVENTOR United States Patent SOUND MUFFLER Salvatore M. Curioni, Dallas, Tex.

Application April 4, 1955, Serial No. 499,100

2 Claims. (Cl. 18167) This invention relates to sound mufflers or reducers and more particularly to such devices adapted to lessen the noise incident to the expansion of gases such as those emanating from the exhaust manifolds of gas fueled engines.

The principal object of the invention is to improve upon contemporary mufflers and noise silencers by providing means for changing the normal rectilineal course of the high velocity exhaust gases into a rotary course while at the same time breaking up or slicing the stream of gases during its rotary progression through the muifier chamber, thereby mollifying to a considerable degree the noise producing effects of the expanding gases.

Another object of the invention is to provide a sound mufiler which consists basically of a cylindrical shell or chamber for the expansion of the exhaust gases but which are constrained in their travel to move in a rotary or serpentinous fashion by means of a helical bafile in the form of a spiral ribbon whose convolutions become increasingly smaller in diameter from one end of the baflle to the other to define a frusto-coniform gate. The plane of the spiral ribbon, in transverse section at any point throughout its length, is perpendicular to the longitudinal axis of the mufiler body or chamber and the convolutions are spaced apart to accommodate a progressive series of concentric vanes so disposed in relation one to the other that the rotary stream of gases is split or sliced and caused to move into and out of the helical bafile between the convolutions thereof while generally traveling toward the outlet end of the muffler shell in a rotary manner, the result being the curbing of the velocity of the gases and a consequent reduction in the noise of exhaust.

Other objects will appear as the description proceeds when considered with the annexed drawing, wherein:

Figure l is a longitudinal sectional view of one form of muffler constructed according to the invention.

Figure 2 is a fragmentary perspective view of the baffle per se.

Figure 3 is a longitudinal sectional view of a modified form of mufiler on a reduced scale.

Figure 4 is a transverse sectional view taken on line 44 of Figure 3, and

Figure 5 is a similar sectional view taken on line 55 of Figure 3.

Referring primarily to Figures 1 and 2 of the drawing, reference numeral denotes generally a cylindrical body or shell 10 having a gas inlet 11 and an outlet 12. At any suitable point within the shell 10 intermediate its ends is installed the baflle, generally indicated by reference numeral 13,-and which constitutes the invention.

The baffle 13 is composed of a continuous ribbon 14 formed into a fiat spiral of frusto-coniform shape. The spiral is connected to the inner wall surface of the shell 10 only around the perimeter of its largest convolution or base and this connection is made preferably by welding at 15. The convolutions 14 are spread apart to provide for the passage there'between of gases entering the shell 10 at its inlet 11 and each convolution provides, in effect,

2,841,235 Patented July 1, 1958 2 a separate concentric baflle member. The normally rectilineal travel of the gases is interrupted by their impingement against the stepped convolutions or baffles defined by the ribbon which, in transverse section at any point throughout its length is situated in a plane perpendicular to the walls of the chamber or shell 10, and, by virtue of the decreasing diameters of the convolutions, a multiplicity of annular baffles is provided to constrain the gases to change from a straight course to a generally circuitous or rotary course toward the outlet end 12 of the shell 10.

To further curb the gases without causing the same to deviate from their rotary course through the chamber, a plurality of arcuate vanes 16 are welded or otherwise secured to the ribbon 14 in the helical space between the convolutions thereof. These vanes are disposed in a plane perpendicular to the plane of the ribbon 14 and are generally tangential with respect to the inner edges of the web or ribbon 14, the inner ends of the vanes being contiguous with the inner edges of the convolutions of the ribbon and extending arcuately outward toward the perirneter of the convolutions. The vanes are equidistantly spaced annularly with their outer ends overlapping their inner ends to impart a swirling motion to the gases within the generally rotary path thereof produced by the spiral bafile. In this manner, the stream of gases which normally travel unrestrictedly in a spiral path is split up into several streams deflected from the common path yet continuing in a progressively spiral manner toward the outlet 12. In this manner, the velocity of the gases is materially reduced by the time they reach the outlet 12 of the chamber 10, hence the noise of exhaust is brought to a minimum.

Welded or otherwise secured to the end of the bafile 13 near the outlet 12 is a disc baflle 17 which further reduces the velocity of the gases seeking release at the outlet 12 by interrupting flow thereof in a straigth line through the axial center of the housing 10.

In Figures, 3, 4 and 5 is shown a modified form of the invention although substantially the same principle is employed. A cylindrical shell or chamber 20 is provided with an inlet 21 and an outlet 22. At any point between the ends of the shell 20, a baffie, generally indicated by reference numeral 23, is installed therein.

The baffle 23 is composed of a plurality of circular plates 24 which are welded or otherwise secured at their peripheries to the inner walls of the shell 20 at longitudinally spaced intervals. Each plate 24 has a central opening 25 therein through which gases pass from one annular chamber 26 to another, these chambers being defined by the plates 24 and intervening disc-like baffles 27.

interposed between the plates 24 and battles 27 is a series of arcuate vanes 22 whose planes are perpendicular to the planes of the plates 24 and baffies 27 to which they are aflixed at their edges as by welding. The vanes 28 are annularly spaced about and are generally tangent to the openings 25 in the plates 24 so that the gases entering each chamber 26 will be constrained by the vanes to leave the chamber in a spiral path and will be constrained by an adjacent plate 24 to enter the next succeeding chamber 26 and so on until the gases are expanded into the shell from whence they escape through the outlet 22 at a much lower velocity and without the usual explosive noise usually attending the exhaust of the gases.

It has been found that by reversing the positions of the vanes 28 in alternate chambers 26 to cause alternate clockwise and counter-clockwise travel of the gases from chamber to chamber, a further reduction in velocity of the gases passing through the muffler may be accomplished with a corresponding reduction in noise of exhaust. It is anticipated that both constant and alternate positions of the vanes may be employed depending upon requirements.

Manifestly, the construction as shown and described is capable of some modification and such modification as may be construed to fall within the scope and meaning of the appended claims is also considered to be within 7 the spirit and intent of the invention.

What is claimed is:

1. A device for reducing the noise of expanding gases comprising a shell into which said gases are expanded at one end and having a gas discharge at its opposite end,

said convolutions effective to break up and impart to said gases a progressive rotary motion to said gases to retard the velocity thereof prior to their discharge from said shell.

2. The structure of claim 1 wherein said relatively spaced means is comprised of a plurality of annular vanes holding the convolutions in spaced apart relationship, said vanes each being disposed perpendicular to said ribbon and generally tangent to the inner edges of said ribbon.

References Cited in the file of this patent UNITED STATES PATENTS 2,511,597 Marx June 13, 1950 FOREIGN PATENTS 123,995 Great Britain May 22, 1917 46,894 France Oct. 30, 1938 (Addition to original 776,345) 

